Sheet punching apparatus and method



Dec. 9, GREENBERG SHEET PUNCHING APPARATUS AND METHOD Fil d Jul 15 19402 Sheets-Sheet l V lNV TOR 52W zoafj wz ATTORNEYS Dec. 9, 1941. J.GREENBERG 2,265,726

SHEET PUNCHING APPARATUS AND METHOD Filed Ju ly 15, 1940 2 Sheets-Sheet2 "I n" In. I I v I ATT'oRNEYs Patented Dec. 9, 1941 UNITED STATESPATENT OFFICE SHEET PUNCHING APPARATUS AND METHOD New York ApplicationJuly 15, 1940, Serial No. 345,482

9 Claims.

This invention relates to a method and apparatus for punching out of rawsheets smaller sheets of particular geometric size and shape, and hasparticular application to the punching out of insulating sheets such asmica for use in electrical condensers.

In making condensers of stacked mica and foil sheets it has been thepractice for an operator to punch out from irregular shaped sheets ofraw mica, the mica insulating sheets of the exact condenser size bymeans of a punch built of the proper dimensions. The selection oftheplaces in theirregular raw sheet from which the punchings were to betaken was left to the discretion of the operator; and the speed ofmaking the punchings and the economy of material depended on theoperators skill, for the more provident the selection of areas to bepunched out, the less waste of material there would be in the originalraw sheet.

By the use of this invention there is obtained an increase in the numberof punchings that can be taken from the raw sheets and without anyspecial skill on the part of the operator, and the number of finishedsheets which can be punched out within a given time is increased.

The invention will be better understood from the following detaileddescription and the accompanying drawings, of which,

Fig. 1 illustrates a sheet of raw material such as mica, which is tohave punchings made in accordance with this invention;

Fig. 2 illustrates a perspective view of a registering punch forpunching registering holes in the sheet of Fig. 1;

Fig. 3 shows a front elevation of the punch of Fig. 21;

Fig. 4 shows a sectional plan view of the punch taken along line 4-4 ofFig. 3;

Fig. 5 illustrates the sheet of Fig. 1 after registering holes have beenpunched in it by the punch of Figs. 2-4;

Fig. 6 illustrates a perspective view of a punch for punching outfinished sheets in accordance with this invention;

Fig. 7 illustrates a sectional plan View of the punch of Fig. 6 takenalong line 1! of Fig. 6;

Fig. 8 illustrates a sectional view of the base portion of the punchtaken along line 8-8 of Fig. '7;

of the punch of Fig. 7 in a difierent punching position from Fig. '7;

Fig. 10 is a view similar to Fig, 9 but in a different punchingposition;

Fig. 11 shows the detail of Fig. 9 in still another punching position;and

Fig. 12 illustrates another fragmentary detail at the base of the punch.

Fig. 1 shows an irregular sheet 9 of suitable material, ordinarily rawmica which has been split to a selected thickness. This is to havepunched out from it smaller sheets of identical size, usuallyrectangular, which are to constitute the insulating sheets of acondenser. A registering punch, illustrated in Figs. 2, 3 and 4 isadapted to punch in the raw sheet registration holes located in relationto the area from which the regular finished sheets are to be punchedout.

The registering punch comprises a base member Ill provided with twofixed upright posts II and M which may be threaded into the base ID. Adie plate I5 is fastened on top of base ID by screws IS. The die plateI5 contains four die holes IT, l8, I9 and 20, these holes beingcontinued all the way through plate IS. 'The base member I 0 is cut awayunder the die holes at 2| so that punchings can be ejected out thebottom. 3

In front of die plate l5 there is fastened to base l0 bybolts 23, aregistering plate 22 having a flat surfaceflush with the surface of thedie plate. There are etched on the plate 22 in front of the die holes, anumber of lines 24 extending parallel to the row of die holes and anumber of other lines 25 perpendicular to lines 24. These lines mark outeight rectangles which correspond to areas which are to bepunched outfrom the raw mica. I I

Mounted on the posts H and I 4 is the punching head, comprising a heavyhead piece 26 having holes 21, and 28, provided with bushings 29 and 30which fit overthe posts H and I4 so that the head can slide up, anddown. A punch aholding plate 3| is fastened centrally to theunder-surface of the head piece 26, and this plate is drilled andthreaded to hold four punches 32, 33, 34 and 35, theupper ends of whichare threaded to screw into the drilled holes of the plate 3 until theshoulders of the lower unthreaded portions of larger diameter of thepunches abut tightly against the plate. The punches have small diameterpunching ends corresponding to the four die holes in the, die plate J l5below. There is heldbelow punch plate 3i Fig. 9 illustrates a detail ofthe base portion a resiliently mounted plate 35 fastened by screws onthe ends of bolts 39 and 40, the heads of which rest on shoulders inholes 4| and 42 in head 26.- Compression springs 3! and 38 serve at tohold the plate rather firmly in its lowermost position. Four holes l2are provided through plate 36, through which the punch ends may and inpractice, the raw mica sheet 9 of Fig. 1

is laid over the register plate as shown in Fig. 4

so that the sheet covers the four die holes andalso all of the etchedlines. brought down, creating registrations in the form of the fourregister holes 43, 44, and'46 (Fig. 5). In this punching operation,plate 36 first bears on the sheet 9, and then compresses springs 31 and38, pushing bolts 39 and) upward in their holes 4| and 42 as the punchescome through the respective holes l2 in plate 36 to enter the die holesand thus perform the punching. For this purpose, the punch may beoperated in a well-known manner by means of a press.

The mica sheet is now ready tobe punched out,

which is done in a second. punch shown in Figs 6 to' 12. This secondpunch comprises a base plate 41 on which is mounted a die plate. 48which maybe fastenedto the base in a suitable manner asby. screws. Y 7

- The die plate 48 contains twodie holes 49 and 59 rectangular inshapeand-of the exact dimension .of. the finished sheets to Joe-punched out.The-base plate is provided with somewhat larger holes 12 under the dieholes through which a the punchings fall out the bottom. In front of 3die plate 48 and also mounted on the base 41 is a plate 5| whichconstitutes the bottom of a rectangularrecess or compartment formed by;three side plates 52, 53 and 54 and the front wall There is located inthe rectangular recess, a rectangularblock 56 which 55Lof the die plate.

is. substantially smaller than the rectangular recess so that the blockis free to move somewhatfrom end to end and backward and frontward.

The dimension. a .by which the block isshorter than the length of thecompartment is equal to thelength a of a punching; and dimension b bywhich the block is narrower than the width of the compartment is equaltothe width b of a punching. 'Block 56 has attached to its upper surfacea plate 51 containing four upwardly protruclin-g. pins 58, 59, 69 and6]- of the exact size and'location to register with the four holespunched in the mica sheet 9. A hand knob 10 is attached to plate 51-sothat the block may be moved from one corner to another-of the recess.

.In thisarrangement, when the block is in any oneof the four compartmentcorners, the four-- pins 58, 59, Stand 6] beat the same relation anddistances to the rectangular die holes asthe registration die holes 11,l8,'l9 and 20 bear to a pair of spaced rectangles marked by the etchedlines-24and25 on the registering punch. The

four pairs of rectangles so related to the pins in.

the four block portions are, respectively, rectangles'l and-3, 2 and4,=5 and I, and 6 and 8.

The base4-1 is provided with two fixed vertical posts 62 and 63 on whichthe punch head slides. The punch .head 64 is provided with holes.containing bushings B5 and 66 on which it is adapted to slide up anddownover the respective posts. There is attached to the under surface ofthe head 64aplate 61 through rectangular holes of The punch is thenwhichthere are fitted tworectangular shaped punches E8 and 69 extendingdownwardly, the heads of which are held against the under side of thehead 64 by the plate 61. The punches may be fastened by providingshoulders under the punch heads which rest on corresponding shoulders inthe rectangular holes through plate 61. These punches 68 and 69 arepositioned to fit within the die holes in plate 48 when the punch isbrought down, so as to stamp out a punching of the same rectangularshape and dimensions.

The raw sheet 9 which has already received the four registration holesis now attached to plate 4 '51 by placing the registration holes overthe four pins so that the main part of the sheet which is to be punchedout extends back over the die plate 48 as shown in Fig. 7. In Fig. '7the raw sheet is shown turned over from its position of Fig. 4. When theblock 56 is moved by the operator to the upper left hand corner of therectangular recess, as shown in Fig. 7, the mica is in position to havethe two finished sheets numbered I and 3 (seeFig. 9) punched out,asthese two areas are over the two die holes in Fig. 7. The block 56.canthen be moved forward so that theblock isin the lower left hand corner.of the recess (Fig. '9) in which position the areas numbered 5 and 1(see Fig. 10) will be punched out. Since the'distance b which the blockmoves forward is'equal to the width b of one. of the punched rectangles,the

front edges of rectangles 5 and I are taken along.

the same lines as the rear edges of previous punched rectangles I and 3,respectively. The

block 56 can then be moved over to the forward.

right corner (Fig. 10), in which position the two rectangles 6 and 8(see Fig. 11) are punched out. When the block is then. moved to the rearright corner (Fig. 11) the last twosheets 2 and 4 are punched out. 7 7

By this punching procedure there will always be obtained from each rawsheet eight finished rectangles which will use up all of the materialwithin the larger rectanglecut out, sothat the wastage of mica will besmall. Furthermore, with each punching operation there will always bepunched out two finished sheets.

It is observed that with the use of this invention it is possible tomake punchings from a number of sheets of raw material at one punchingoperation; for a number of the sheets like that of Fig, 5 which havebeen individually indexed in the indexing punch of Fig. 2, can be placedone over another on the indexingpins of the punch of Fig. 6, and thepunch then operated as has already been described to make the punchingsfrom the several sheets at once.

It should be understood that the relation of the spacing between thepunches to the punch dimensions need-not necessarily be such as to leaveno material whatever. between the punched rectangles, for if the punchesare spaced somewhat further apart some material will be left. But thegreater the punch spacing the greater may be the wastage, for acorrespondingly greater area will then have to be created within theetched lines 24 and 25 of the registering punch, which would requiresheet 9 to be larger in order to cover the'area from which punchings aretaken. 7

It will also be understood that the etched lines 24 and 25 which liewithin the extrerne bounding lines 24 and 25 need not be present, .asthe presence of these interior lines is only for convenience in showinghow many punchings can be taken from a raw sheet in case the sheet istoo small to take the entire eight punchings from it.

It would be possible, of course, to increase the number of punches. Forexample, three spaced punches might be used, in which case twelvecondenser sheets could be punched out of each raw sheet in the fourblock positions. This would require a corresponding increase in the areawithin etched lines 24 and 25 of the registering punch, andcorrespondingly larger raw sheets 9 would be used.

I claim:

1. A sheet punching device comprising a rectangular punch and acorresponding die, a rectangular compartment near the die, a rectangularblock in the compartment movable to each corner of the compartment, thelength of the block being at least as much shorter than the length ofthe compartment as the length of said punch, and the width of the blockbeing at least as much narrower than the width of the compartment as thewidth of said punch, and a holding device on the block for fixing thesheet in position on the block so that the sheet extends over the die.

2. A sheet punching device comprising a plurality of equal sized punchesand a plurality of dies positioned to cooperate with the punches, saidpunches being spaced apart by a distance at least as great as the lengthof the punches, a compartment near the die having a plurality ofcorners, a block in the compartment movable from one corner to another,and a fastening device on the block for fixing the sheet in positionthereon, the distances through which the block moves in going from onecorner to the next being sufilcient to bring entirely different portionsof the sheet over the die every tim the block is moved from one cornerto the next.

3. A sheet punching device comprising a plurality of equal sizedrectangular punches and a plurality of dies positioned to cooperate withthe punches, said punches being spaced apart by a distance equal to thelength of the punches, a compartment of rectangular shape, a block ofrectangular shape movable from one corner of the compartment to another,the length of said block being as much shorter than the length of thecompartment as the distance between said punches, and the width of theblock being as much narrower than the width of the compartment as thewidth of said punch, and a holding device on the block for fixing thesheet in position on the block so that the sheet extends over the dies.

4. Sheet punching apparatus comprising a template marking the area to bepunched out of a raw sheet, a plurality of registration punches near thetemplate for punching registration holes in the sheet, a sheet punch forpunching finished sheets out of said area, a platform adjacent saidsheet punch, a plurality of registration pins on said platform of thesame spacing and thickness as said registration punches, said platformbeing movable to a plurality of different positions in each of which theregistration pins bear the same relative location and distance from thesheet punch as the registration punches bear to a corresponding area ofsaid template.

5. Sheet punching apparatus comprising a template marking the area to bepunched out of a raw sheet, a registration punch near the template, asheet punch for punching finished sheets out of said area, a platformadjacent said sheet punch, registration means on said platform havingthe same registering dimensions as said registration punch, saidplatform being movable to a plurality of different positions in each ofwhich the registration means bears the same relative location anddistance from the sheet punch as the registration punch bears to acorresponding area of said template.

6. Sheet punching apparatus comprising a template marking the area to bepunched out of a raw sheet, a registration punch near the template, asheet punch and die mechanism comprising a plurality of spaced dies andcorresponding punches for punching out finished sheets from the saidarea, a platform adjacent said mechanism, registration means on saidplatform of the same registering dimensions as said registration punch,said platform being movable to a plurality of different positions ineach of which the registration means bears the same relative locationand distances from the dies as the registration punch bears tocorresponding areas of said template.

7. The method of punching out areas from a raw sheet which comprisesplacing said sheet over a template, punching a registration mark in thesheet while so placed, registering said mark with a correspondingregistering device on a movable platform, moving said platform tosuccessive positions, and punching out said areas in each position.

8. The method of punching out areas from raw sheets which comprises,placing the sheets over a template and punching registration holes inthe sheets while so placed, then placing the registration holes of aplurality of the sheets thus registered over a corresponding registeringdevice on a movable platform, moving said platform to successivepositions, and punching out said areas in each position.

9. A sheet punching device comprising a plurality of equal-sizedrectangular punches and a plurality of dies positioned to cooperate withthe punches, said punches being spaced apart by a distance equal to thelengths of the punches, a platform movable to any of four positionswhich are relatively located as corners of a rectangle, the distance ofplatform movement from one position to the next in the directionparallel to the lengths of the punches being equal to the lengths of thepunches, and the distance through which the platform moves in thedirection perpendicular to the first-mentioned direction being equal tothe widths of the punches, and a holding device on the platform forfixing the sheet in position to extend over the dies.

JACK GREENBERG.

